Play has been difficult to define because it is an aspect of many activities rather than of just a specific kind of activity. Classic theorists such as Piaget and Vygotsky emphasized representational play as play in its purist form, but both immediate and ultimate functions of play can be discerned in simple physical activity play. (Author)

Proposes that humans may have evolved a special sensitivity to certain types of social information during rough-and-tumble play that facilitates social cognition. Describes the cognitive benefits of physical play as providing a break from demanding intellectual tasks and hypothesizes that physical play is related to gender differences in spatial…

Considers areas of consensus from commentaries, including the value of an evolutionary perspective and the utility of exploring variations in physical activity play. Examines areas of debate, including the nonplay-play distinction, functions of rough-and-tumble play, and the opportunities of juveniles for exercise training. Calls for more directed…